OROVILLE, Calif. (AP) — A 26-year-old man has been accused of igniting a destructive California wildfire in early July by throwing a firework from a car window during hot, dry and windy weather.

Spencer Grant Anderson, of Oroville, was charged Monday after weeks of continuous surveillance by investigators, the Butte County District Attorney’s Office said.

The Thompson fire scorched nearly 6 square miles (15.5 square kilometers), destroyed 13 homes and damaged others in the Oroville area of the northern Sacramento Valley.

Anderson was jailed on a no-bail hold after appearing in court to face charges including arson of an inhabited structure, arson of forest land, and arson causing multiple structures to burn, the prosecutor’s office said in a statement.

Anderson will return to court Wednesday to set further dates to enter a plea and for pretrial hearings, the office said.

“It was a long investigation, there was a lot moving parts to it,” Larry Pilgrim, Anderson’s attorney, told The New York Times. “He is just being accused at this point.” Pilgrim did not immediately return messages from The Associated Press seeking comment.

The fire erupted shortly before 11 a.m. on July 2 when temperatures were above 100 degrees (38 Celsius), humidity was low and high winds were blowing, authorities said.

A car seen at the location of the fire’s start led to identification of Anderson the next day and lengthy surveillance as investigators built their case, concluding that a flaming object was thrown from the vehicle, the office said.

Warrants were served on Aug. 22, and Anderson was arrested. Authorities allege that during questioning, he admitted that he purchased fireworks in Oroville and went to the location to test one by throwing it out of his car window.